The process could help convert millions of tons of plastic that we generate each year into a fuel similar to gasoline and diesel.
The world is drowning in plastic. Every year, more than 300 million tons of plastic find their way to a landfill or the environment, where it will take hundreds of years to break down and kill all kinds of wildlife in the meantime.
A team of chemists at Purdue may have found a partial solution to our plastic problems. As detailed in an article published this week in Sustainable Chemistry and Engineering, chemists discovered a way to convert polypropylene, a type of plastic commonly used in toys, medical devices, and packaging for products such as potato chip bags, into gasoline and diesel-like fuel. . The researchers said this fuel is pure enough to be used as a blended blend, a major component of fuel used in motor vehicles.
Polypropylene waste accounts for nearly a quarter of the roughly 5 billion tons of plastic that have accumulated in the world’s landfills in the last 50 years.
To convert polypropylene into fuel, the researchers used supercritical water, a phase of water that demonstrates the characteristics of a liquid and a gas under pressure and temperature conditions. Purdue chemist Linda Wang and her colleagues heated the water to between 716 and 932 degrees Fahrenheit at pressures approximately 2,300 times greater than atmospheric pressure at sea level.
When purified polypropylene residue was added to the supercritical water, it turned to oil within a few hours, depending on the temperature. At about 850 degrees Fahrenheit, the conversion time dropped to less than an hour.
By-products of this process include gasoline and diesel-like oils. According to the researchers, its conversion process could be used to convert roughly 90 percent of the world’s polypropylene waste each year into fuel.
“Disposing of plastic waste, whether it is recycled or discarded, is not the end of the story,” said Wang. “Plastics degrade slowly and release microplastics and toxic chemicals into land and water. “This is a catastrophe because once these pollutants are in the oceans, they are impossible to fully recover.”
The obvious benefit of this new conversion process is cleaning up the environment by finding a use for plastic waste. But as Wang noted in a statement, the fact that the produced fuel can be sold for profit will also encourage the recycling industry to adopt it quickly.
In fact, as Wang pointed out, time is of the essence when it comes to implementing effective recycling strategies. Every year that nothing is done, millions of tons of plastic flow into the oceans, where they are swallowed up by wildlife and kill coral reefs. This plastic is very difficult to clean and poses a growing threat to entire ocean ecosystems, potentially leading to a cascading environmental crisis around the world.
It’s unclear how difficult it will be to implement this new plastic converting process to scale, but at least for once it looks like there could be a “great future for plastics.”
